Understanding RPR-IEEE

RPR, as described in IEEE 802.17, is a metropolitan area network (MAN) technology supporting data transfer among stations interconnected in a dual-ring configuration. The IEEE 802.17b spatially aware sublayer amendment is not yet ratified but is expected to add support for bridging to IEEE 802.17. Since the amendment is not yet ratified, no equipment is currently IEEE 802.17b compliant. The ML-Series card's RPR-IEEE is based on the expected IEEE 802.17b based standard.

The ML-Series card supports RPR-IEEE. RPR-IEEE is well suited for transporting Ethernet over a SONET/SDH ring topology and enables multiple ML-Series cards to become one functional network segment. When used in this role, RPR-IEEE overcomes the limitations of earlier schemes, such as IEEE 802.1D Spanning Tree Protocol (STP), IEEE 802.1W Rapid Spanning Tree Protocol (RSTP), and SONET/SDH.

•Fairness. Fairness allows all the stations on the ring to fairly share the RPR-IEEE's best-effort bandwidth.

Role of SONET/SDH Circuits

The ML-Series cards in an RPR-IEEE must connect directly or indirectly through point-to-point synchronous transport signal/synchronous transport module (STS/STM) circuits. The point-to-point STS/STM circuits are configured on the ONS node through Cisco Transport Controller (CTC) or Transaction Language One (TL1) and are transported over the ONS node's SONET/SDH topology on either protected or unprotected circuits.

On circuits unprotected by the SONET/SDH mechanism, RPR-IEEE provides resiliency without using the capacity of the redundant protection path that a SONET/SDH protected circuit would require. This frees this capacity for additional traffic. RPR-IEEE also utilizes the bandwidth of the entire ring and does not block segments like STP or RSTP.

An RPR-IEEE is made up of dual counter-rotating rings (ringlets), one for clockwise or west data traffic and one for counter-clockwise or east data traffic. The ringlets are identified as Ringlet 0 and Ringlet 1 in Figure 26-1. The west ringlet traffic is transmitted out the west interface and received by the east interface. The east ringlet traffic is transmitted out the east interface and received by the west interface. Only east-to-west or west-to-east transmission schemes are allowed.

Figure 26-1 Dual-Ring Structure

RPR-IEEE Framing Process

The ML-Series card transports data around the RPR-IEEE through packet-over-SONET/SDH (POS) circuits. With POS, the RPR-IEEE frame is encapsulated into the SONET/SDH payload for transport over the SONET/SDH topology. For more information about POS, see Chapter 20 "POS on ONS Ethernet Cards."

Table 26-1 defines the most important fields in the RPR-IEEE data frame.

Table 26-1 Definitions of RPR-IEEE Frame Fields

Field

Definition

MAC Destination Address (MAC da)

A forty-eight-bit field specifying the destination as a multicast MAC address or the MAC address of a specific ML-Series card in the RPR-IEEE.

MAC Source Address (MAC sa)

A fourth-eight-bit field specifying the MAC address of a specific ML-Series card in the RPR-IEEE as the source.

Base Control

A field that includes the ring indicator (RI) bit, the fairness eligible (FE) bit, the frame type (FT) bit, and the service class (SC) bit.

TTL Base

A field that contains the time to live (TTL) setting. The sending station sets the TTL, which remains unchanged for the life of the packet.

Extended Control

A field that contains the flood indicator (FI) bit and the strict order (SO) bit.

Extended DA

A forty-eight-bit field specifying the MAC address of the ultimate destination.

Extended SA

A forty-eight-bit field specifying the MAC address of the ultimate source.

Figure 26-3 illustrates the RPR-IEEE topology and protection control frame. Topology and protection (TP) frames are usually sent to the broadcast address.

Figure 26-3 Topology and Protection Control Frame Formats

Figure 26-4 illustrates the RPR-IEEE fairness frame. Fairness frames are sent either to all stations or only the nearest neighbor depending on whether it is a single-choke fairness frame (SCFF) or multi-choke fairness frame (MCFF). Fairness frames are included in the total bandwidth of the QoS A0 service class. This eliminates the need for a destination address (DA). The MCFF type also includes an additional frequency division duplexing (FDD) frame to help smooth the fairness variation. The field SA Compact is the address of the station providing the fair rate.

Note The ML-Series card supports multi-choke fairness frames from other stations on the RPR-IEEE. The ML-Series card does not generate these frames.

CTM and RPR-IEEE

Cisco Transport Manager (CTM) is an element management system (EMS) designed to integrate into an overall network management system (NMS) and interface with other higher level management tools. CTM supports RPR-IEEE provisioning on ML-Series cards. For more information, refer to the Cisco Transport Manager User Guide at:

Configuring the Attribute Discovery Timer

Because station attributes are communicated separately from topology and protection packets, there is a separate timer to control the frequency at which these packets are sent. Attribute propagation is therefore determined by the attribute discovery (ATD) timer. The default rate is one packet per second for each ringlet.

Note Configure both ringlets with the same value.

To enable and configure the ATD, perform the following procedure, beginning in global configuration mode:

Configuring the Reporting of SONET Alarms

The ML-Series card reports SONET/SDH alarms through the CTC alarm panel in the same manner as other ONS cards. The ML-Series card can also report SONET/SDH alarms through the Cisco IOS command-line interface (CLI). Configuring CTC reporting does not affect Cisco IOS CLI reporting or vice-versa.

To configure the reporting of SONET/SDH alarms on the Cisco IOS CLI, perform the following procedure, beginning in global configuration mode:

Configuring RPR-IEEE Protection

RPR-IEEE has three protection states:

•Closed—This is the normal steady state. Data traffic is traveling around the RPR-IEEE on both Ringlet 0 and Ringlet 1. Figure 26-1 illustrates this state.

•Open—This is the state after a protection event. A protection event, such as a fiber cut or node failure, triggers a change in the ring topology. Each node responds to the new topology by steering. Steering forwards data traffic so that it avoids the failure. Based on the type of failure, it will avoid either a specific span or a node and its two adjoining spans. Figure 26-5 illustrates this state.

•Passthrough—This is the initial state of the RPR-IEEE node. It does not participate in the topology and blindly forwards frames.

Figure 26-5 Each RPR-IEEE Node Responding to a Protection Event by Steering

You can modify many of the RPR-IEEE protection characteristics with the procedures in the following sections.

Configuring the Hold-off Timer

You can delay the protection response to a failure event, such as a signal failure or signal degradation, with the hold-off timer. Setting a longer timer can help avoid link errors that last long enough for detection, but do not last long enough to warrant the costs of protecting the span. This delay can result in higher traffic loss, however. The default value for this timer is 0 milliseconds.

To enable and configure the hold-off timer, perform the following procedure, beginning in global configuration mode:

Specifies the delay before a protection response is sent. Values range from 0 to 20, in units of 10 milliseconds. The default is 0.

(Optional) You can also specify the east or west ringlet.

Caution The number of milliseconds for the keepalive timer must be higher than the number of milliseconds for the holdoff timer.

Caution When using SW-LCAS on the RPR-IEEE, the addition or deletion of a SW-LCAS member circuit causes a traffic hit with a maximum of 50 m/sec. The holdoff timer requires a value greater than 5 (50 m/sec) or the SW-LCAS addition or deletion triggers a protection response

Step 3

Router(config)# no shut

Enables the RPR-IEEE interface and changes the mode from the default passthrough.

jumbo—Enables handling of frames in excess of the standard size, up to a maximum size of 9100 bytes. A jumbo-enabled station changes the interface MTU to 9100 bytes if all stations in the ring are jumbo enabled. A message is generated to indicate that the ring supports jumbo frames when all stations are configured for this preference.

The default is to not support jumbo frames.

Step 3

Router(config)# no shut

Enables the RPR-IEEE interface and changes the mode from the default passthrough.

forced-switch—Precedes all other failure events on a ring for the span on which it is configured. The operation protects the span indicated by the command. In the case of steering, forwarding uses only the topology list for the opposite span. A forced switch is saved in the configuration.

manual-switch—Behaves similarly to a forced switch, in that it coerces a reaction from the protection system. The difference is that this configuration can be usurped by higher-level requests detected on the configured or the opposite span. A manual switch is not saved in the configuration. Configuring a manual switch on a span that has a forced switch configured will clear the forced switch.

Note When a manual switch is configured, it will neither display in the running configuration nor save to the startup configuration.

You must specify whether the switch is to take place on the east or west ringlet.

Step 3

Router(config)# no shut

Enables the RPR-IEEE interface and changes the mode from the default passthrough.

Configuring Protection Timers

Protection messages are sent based on the intervals of two timers. These timers apply under different circumstances:

•Fast timer—Immediately after a protection event occurs, a fast protection timer is used. This timer is configured between 1 and 20 milliseconds to cause a rapid acknowledgement of the protected state on the ring. A finite number of packets are sent at this frequency after the event. The default for this timer is 10 milliseconds.

•Slow timer—Between protection events, the slow timer communicates the current protection state of the ring. This timer is configured from 1 to 10 in units of 100 milliseconds. The default is 10, which represents 100 milliseconds.

The protection timers are configured the same on both spans of an interface.

To enable and configure the protection timers, perform the following procedure, beginning in global configuration mode:

Configuring the Wait-to-Restore Timer

When the failure is fixed, a wait-to-restore timer defines how long before the span reverts to its original state. This timer protects against false negatives in the detection of the failure status, which can avoid protection-flapping through the use of larger values. Smaller values result in faster recovery times, however. This timer can be configured between 0 and 1440 seconds, or configured to not recover automatically. The default for the timer is 10 seconds.

To enable and configure the wait-to-restore timer, perform the following procedure, beginning in global configuration mode:

Configuring Keepalive Events

A station receives fairness messages from a link to determine its status. When the number of milliseconds that pass without receiving a fairness message from the neighboring stations exceeds a specified timer, a keepalive event is triggered. The keepalive event generates a protection event.

The timer can have a different value on each span and must be greater than or equal to the hold-off timer. This feature is independent of the fairness algorithm itself, but is still a function performed by the fairness machine.

To enable and configure the keepalives, perform the following procedure, beginning in global configuration mode:

Specifies the amount of time that can pass before a keepalive event is triggered after not receiving a fairness message from a neighboring station. Values range from 2 to 200 milliseconds. The default is 3 milliseconds.

(Optional) You can also specify the east or west ringlet.

Caution The number of milliseconds for the keepalive timer must be higher than the number of milliseconds for the holdoff timer.

Step 3

Router(config)# no shut

Enables the RPR-IEEE interface and changes the mode from the default passthrough.

Configures the threshold for the CRC errors on the RPR-IEEE span. The threshold is the percentage of received, continuously CRC-errored frames required during the delay period (soak time). When the threshold is crossed, the excessive crc alarm is declared. This also triggers the CRC error action, if one is configured.

For crc-error-rate, specify the CRC packet error rate variable in the range from 2 to 4. The error rate variable corresponds to the CRC error rate as a percentage of traffic.

•2 is 10e-2 or 1% of traffic (1 CRC error in100 frames).

•3 is 10e-3 or 0.1% of traffic. (1 CRC error in1000 frames).

•4 is 10e-4 or 0.01% of traffic (1 CRC error in10000 frames).

The default threshold is 3.

(Optional) You can also specify the east or west ringlet.

Step 3

Router(config-if)# trigger crc-error action {east | west | <cr>}

Specifies whether excessive CRC errors shut down the span. The default is for excessive CRC errors not to shut down the span.

(Optional) You can also specify the east or west ringlet.

Caution The user must configure both spans to shut down on receiving excessive CRC errors. With the default behavior of both spans not shutting down, network problems can occur if the ML-Series card receives signal degrade (SD) while in passthrough mode.

(Optional) Sets the number of minutes that CRC errors must exceed the threshold (soak) before an action is taken. For soak-minutes, the range is from 3 minutes to 10 minutes. The default is 10 minutes.

(Optional) You can also specify the east or west ringlet.

Step 5

Router(config)# no shut

Enables the RPR-IEEE interface and changes the mode from the default passthrough.

Configuring QoS on RPR-IEEE

With this different priorities of traffic can be configured with rate limiters and prescribed specific bandwidths. This configuration on each span might be identical (default) or might vary from the other span.

Class A

Class A is highest priority, lowest latency, and lowest jitter class . A has two types - A0 and A1. Can reserve a portion of the ringlet bandwidth using "reserve" keyword. This bandwidth is known as A0 bandwidth. The A0 bandwidth can only be used for classA traffic. Any Reserved bandwidth that is unused will remain unused on the ring, Reserved bandwidth is therefore expensive because it reduces the bandwidth available for best effort. This reservation is propagated throughout the ringlet, and all RPR stations recognize the bandwidth allocation cumulatively. Reserved A0 bandwidth can be used only by the station that reserves it. The default allocation is 0 Mbps. The unreserved classA bandwidth is called the A1 bandwidth. Service class A1 is configured as high-priority traffic in excess of the A0 bandwidth reservation, and can be rate-limited using the high tx-traffic rate limiter. The default allocation for A1 is 5 Mbps.

ClassB

This is the medium traffic priority. Lower priority than classA, but higher priority than classC. The medium transmit traffic rate limiter allows a certain amount of traffic to be added to the ringlet that is not subject to fairness eligibility, but must compete for the unreserved bandwidth with other traffic of the same service class. This traffic is committed information rate (B-CIR) traffic. The default allocation is 10 Mbps.

ClassC

MQC -IEEE RPR CLI Characteristics

•IEEE-RPR classes are applicable to both front end and RPR-IEEE interfaces.

•A MQC class in a policy map can be mapped to one of the RPR classes using "set rpr-ieee service class". By default the MQC class maps to IEEE-RPR class C.

•RPR classes B and C support Weighted Round Robin scheduling for multiple MQC classes mapping to RPR class A and B. MQC classes mapped to RPR class A gets mapped to one stream, while each MQC class mapped to RPR class B or C gets mapped to a seperate stream.

•The "Bandwidth percent" action is supported for MQC classes mapping to RPR class B and C. The bandwidth percent for these MQC classes defines the proportion of b/w these class B and C stream will get, out of total b/w available to class B and C (whatever remains after class A traffic) . Both these RPR classes allow 100% each. Trying to assign more than 100% will be rejected with an error .

Configuring Fairness Weights

RPR-IEEE has a configurable fairness system, used to control congestion on each ringlet. This feature moderates bandwidth utilization of the ringlet to minimize and potentially eliminate starvation of any station. Each station has two instances of the fairness machine, to control traffic that is being transmitted and transited out of each span of the interface. Each fairness machine is devoted to a particular ringlet, and controls the traffic that is destined to that ringlet.

Each ringlet in an unwrapped ring is independent, and the fairness configuration can differ for each direction. The default is to configure both directions, but you can optionally specify east or west in the configuration.

The local station weight impacts how congested the station appears relative to other stations in the ringlet. It also affects how much more bandwidth a station can use. A higher weight gives the local station a greater share of the ringlet bandwidth. A lower weight decreases the bandwidth share of the local station. The default value is 0 configured as an exponent of 2, which yields an effective weight of 1.

To enable and configure the fairness weight, perform the following procedure, beginning in global configuration mode:

Configuring RPR-IEEE Service Classes Using the Modular QoS CLI

Traffic is directed to the three service classes supported by RPR-IEEE by using the standard Cisco Modular QoS CLI (MQC). MQC is a CLI structure that allows you to create traffic policies and attach these policies to interfaces. A traffic policy contains a traffic class and one or more QoS features. A traffic class classifies traffic, while the QoS features in the traffic policy determine how to treat the classified traffic.

For more information on general MQC configuration, refer to the following Cisco IOS documents:

Caution The
cos priority-mcast command is not supported under RPR-IEEE on the ML-Series card or accepted. The command incorrectly shows as an option under the Cisco IOS CLI.

Caution In IEEE-RPR mode if additional class maps are added to a policy map and associated the policy map with a output interface even if no bandwidth is reserved explicitly, by default 7% bw is allocated and once the bandwidth reaches more thant 100% further class-map configuration on that policy-map is rejected.

To enable and configure the RPR-IEEE service classes with the MQC, perform the following procedure, beginning in global configuration mode:

Command

Purpose

Step 1

Router(config)# class-map match-any class-name

Specifies the user-defined name of the traffic class and the logical OR operator for all matching statements under this traffic class.

Specifies an IP precedence value (0 to 7) used as match criteria or specifies an IP precedence traffic label.

Each value variable is mapped to a specific label variable. Entering the command with a ? in place of the ip-precedence-value | ip-precedence-traffic-label variable reveals the labels and their corresponding values.

Step 3

Router(config)# exit

Exits class mode.

Step 4

Router(config)# policy-map policy-name

Specifies the name of the service policy to configure. Service policies link the configured class maps to Layer 2 traffic priorities, or in this case, the three service classes of RPR-IEEE.

Note An assignment has to be constructed for each class map.

Step 5

Router(config)# class class-name

Specifies the name of a predefined class, which was defined with the class-map command, to be included in the service policy.

Note Each of the three RPR-IEEE classes must be configured as described in this procedure.

Step 6

Router(config)# set rpr-ieee service-class {a | b | c}

Specifies the appropriate RPR-IEEE service class for the class. The three classes correspond to each of the three RPR-IEEE service classes. Only one service class can be configured for each MQC class.

Step 7

Router(config)# exit

Exits class mode.

Step 8

Router(config)# no shut

Enables the RPR-IEEE interface and changes the mode from the default passthrough.

Configuration Example for RPR-IEEE QoS

The following sample configurations are for RPR-IEEE QoS. Example 26-1 details a simple QoS configuration. Example 26-7 details a more complex configuration. The configuration on your network will differ based on your network design.

Configuration Example Using MQC to Configure Simple RPR-IEEE QoS

The following is an example of the configuration process for the three RPR-IEEE service classes:

Note The ip address field in the output of show rpr-ieee topology detail is populated only by the IP address that is applied to the rpr 0 main interface. It is not populated by the IP address of any of the sub-interfaces.

Configuring RPR-IEEE End-to-End

You need to use both CTC and Cisco IOS to configure RPR-IEEE for the ML-Series card. CTC is the graphical user interface (GUI) that serves as the enhanced craft tool for specific ONS node operations, including the provisioning of the point-to-point SONET/SDH circuits required for RPR-IEEE. Cisco IOS is used to configure RPR-IEEE on the ML-Series card and its interfaces.

Note You can use TL-1 to provision the required SONET/SDH point-to-point circuits instead of CTC.

Provisioning Card Mode

The first task in creating an end-to-end RPR-IEEE is to set the CTC card mode to 802.17. For more information on this task, see the "Provisioning Card Mode" section.

Connecting the ML-Series Cards with Point-to-Point STS/STM Circuits

You connect the ML-Series cards in an RPR-IEEE through point-to-point STS/STM circuits. These circuits use the ONS 15454 SONET/SDH network and are provisioned using CTC in the same general manner as provisioning ONS 15454 SONET/SDH optical circuits. After putting the ML-Series card in RPR-IEEE mode and creating the circuits through CTC, further provisioning of the ML-Series card is done through the Cisco IOS CLI. It is assumed that the SONET/SDH node and its network are already active.

Guidelines for Connecting the ML-Series Cards with Point-to-Point STS/STM Circuits

These are some general guidelines for configuring the circuits required by RPR-IEEE:

•You must configure SONET/SDH circuits in an east-to-west configuration, from Port 0 (east) to Port 1 (west) around the SONET/SDH ring. The ports are labeled East and West in the CTC card-level view of the ML-Series card being provisioned and in the CTC Circuit Creation Wizard. The east-to-west provisioning is enforced by the network control program (NCP). The east-to-west setup is also required in order for the CTM network management software to recognize the ML-Series configuration as an RPR-IEEE.

Detailed CTC circuit procedures are available in the NTP-A343, "Create an Automatically Routed OC-N Circuit," and the NTP-A344, "Create a Manually Routed OC-N Circuit," procedures in the "Create Circuits and VT Tunnels" chapter of the Cisco ONS 15454 Procedure Guide and in the NTP-D323, "Create an Automatically Routed High-Order Circuit," and NTP-D 324, "Create a Manually Routed High-Order Circuit," procedures in the "Create Circuits and Tunnels" chapter of the Cisco ONS 15454 SDH Procedure Guide.

Example of Connecting the ML-Series Cards with Point-to-Point STS/STM Circuits

The three-node RPR-IEEE in Figure 26-6 shows an example of the point-to-point circuits needed.

Figure 26-6 Three Node RPR-IEEE Example

To configure the circuits for the example, you would need to perform these tasks in CTC:

1. Create a circuit from Node 1, East Span to Node 2, West Span.

2. Create a circuit from Node 2, East Span to Node 3, West Span.

3. Create a circuit from Node 3, East Span to Node 1, West Span.

Creating the RPR-IEEE Interface and Bridge Group

The plug-n-play feature of RPR-IEEE automatically discovers topology and advertises station capabilities. This allows ML-Series cards to become operational without manual intervention when the ML-Series card is in 802.17 mode and the SONET/SDH circuits are configured. Unlike Cisco proprietary RPR, RPR-IEEE does not require the user to configure POS interfaces.

The additional Cisco IOS CLI provisioning needed to set up basic, functional RPR is straightforward. The user needs to complete these tasks:

Caution A duplicate MAC address on the RPR-IEEE can cause network problems.

Understanding the RPR-IEEE Interface

When the card mode is changed to IEEE 802.17, the physical rpr-ieee interface is automatically created. It provides all the normal attributes of a Cisco IOS virtual interface, such as support for default routes.

An rpr-ieee interface is considered a trunk port, and like all trunk ports, subinterfaces must be configured for the rpr-ieee interface to join a bridge group.

The POS interfaces are not visible or configurable in 802.17 card mode.

Understanding the RPR-IEEE Bridge Group

The default behavior of the ML-Series card is that no traffic is bridged over the RPR-IEEE even with the interfaces enabled. This is in contrast to many Layer 2 switches, including the Cisco Catalyst 6500 series and the Cisco Catalyst 7600 series, which forward VLAN 1 by default. The ML-Series card will not forward any traffic by default, including untagged or VLAN 1 tagged packets.

For any RPR-IEEE traffic to be bridged on an ML-Series card, a bridge group needs to be created for that traffic. Bridge groups maintain the bridging and forwarding between the interfaces on the ML-Series card and are locally significant. Interfaces not participating in a bridge group cannot forward bridged traffic. The bridge group enables data transport across the RPR-IEEE infrastructure.

Figure 26-7 illustrates a bridge group spanning the ML-Series card interfaces, including the rpr-ieee virtual interface.

Figure 26-7 RPR-IEEE Bridge Group

Caution All Layer 2 network redundant links (loops) in the connecting network, except the RPR-IEEE topology, must be removed for correct RPR-IEEE operation. Or if loops exist, you must configure STP/RSTP.

Enters interface configuration mode to configure the Ethernet interface that you want to include in the bridge group.

Step 3

Router(config-if)# bridge-groupbridge-group-number

Assigns the network interface to a bridge group.

Note You can safely ignore the baby giant frames warning that may appear.

Step 4

Router(config-if)# no shutdown

Changes the shutdown state to up and enables the interface.

Step 5

Router(config)# interface rpr-ieee 0

Creates the rpr-ieee interface on the ML-Series card or enters the rpr-ieee interface configuration mode. The only valid rpr-ieee number is 0.

Step 6

Router(config-if)# rpr-ieee protection prefjumbo

Enables jumbo frame capability on the RPR-IEEE interface:

jumbo—Enables handling of frames in excess of the standard size, up to a maximum size of 9100 bytes. A jumbo-enabled station changes the interface MTU to 9100 bytes if all stations in the ring are jumbo enabled. A message is generated to indicate that the ring supports jumbo frames when all stations are configured for this preference.

The following examples show RPR-IEEE configurations. Example 26-7 is a simple configuration. It does the minimum needed to bridge the ML-Series card's Ethernet ports and the ML-Series card's RPR-IEEE and leaves the RPR-IEEE characteristics at default. Example 26-8 is a complex example of RPR-IEEE with multiple bridge groups, configured characteristics, and QoS.

Example 26-7 Configuration Example for Simple RPR-IEEE

version 12.2

no service pad

service timestamps debug datetime msec localtime

service timestamps log datetime msec localtime

no service password-encryption

service internal

!

hostname ml

!

boot-start-marker

boot-end-marker

!

enable password x

!

clock timezone PST -8

clock summer-time PDT date Apr 2 2006 2:00 Oct 29 2006 2:00

ip subnet-zero

no ip routing

no ip domain-lookup

!

no mpls traffic-eng auto-bw timers frequency 0

!

bridge irb

!

!

interface GigabitEthernet0

no ip address

no ip route-cache

no ip mroute-cache

bridge-group 10

bridge-group 10 spanning-disabled

!

interface GigabitEthernet1

no ip address

no ip route-cache

no ip mroute-cache

shutdown

!

interface RPR-IEEE0

no ip address

no ip route-cache

rpr-ieee fairness mode aggressive

!

interface RPR-IEEE0.10

encapsulation dot1Q 10

no ip route-cache

no snmp trap link-status

bridge-group 10

bridge-group 10 spanning-disabled

!

ip classless

no ip http server

Example 26-8 Configuration Example for a Complex RPR-IEEE

version 12.2

no service pad

service timestamps debug datetime msec localtime

service timestamps log datetime msec localtime

no service password-encryption

service internal

!

hostname ml

!

boot-start-marker

boot-end-marker

!

enable password x

!

clock timezone PST -8

clock summer-time PDT date Apr 2 2006 2:00 Oct 29 2006 2:00

ip subnet-zero

no ip domain-lookup

!

vlan dot1q tag

no mpls traffic-eng auto-bw timers frequency 0

!

bridge irb

!

!

interface GigabitEthernet0

no ip address

bridge-group 12

bridge-group 12 spanning-disabled

!

interface GigabitEthernet1

no ip address

mode dot1q-tunnel

bridge-group 22

bridge-group 22 spanning-disabled

!

interface RPR-IEEE0

ip address 11.1.1.1 255.255.255.0

trigger crc-error threshold 4 east

trigger crc-error threshold 4 west

trigger crc-error action east

trigger crc-error action west

trigger crc-error delay 3 east

trigger crc-error delay 3 w

rpr-ieee atd-timer 10

rpr-ieee protection wtr-timer 60

!

interface RPR-IEEE0.1

encapsulation dot1Q 1 native

ip address 10.1.1.4 255.255.255.0

no snmp trap link-status

!

interface RPR-IEEE0.10

encapsulation dot1Q 10

no snmp trap link-status

bridge-group 10

bridge-group 10 spanning-disabled

!

interface RPR-IEEE0.12

encapsulation dot1Q 12

ip address 1.1.1.12 255.255.255.0

no snmp trap link-status

bridge-group 12

bridge-group 12 spanning-disabled

!

interface RPR-IEEE0.22

encapsulation dot1Q 22

no snmp trap

bridge-group 22

bridge-group 22 spanning-disabled

!

interface RPR-IEEE0.800

encapsulation dot1Q 800

ip address 8.1.1.1 255.255.255.224

no snmp trap link-status

!

ip classless

no ip http server

!

!

snmp-server community public RW

snmp-server ifindex persist

snmp-server trap link ietf

snmp-server host 64.101.18.178 version 2c public

snmp-server host 64.101.18.193 version 2c public

!

!

control-plane

!

line con 0

exec-timeout 0 0

line vty 0 4

exec-timeout 0 0

no login

end

Verifying RPR-IEEE End-to-End Ethernet Connectivity

After successfully completing the procedures to provision an RPR-IEEE, you can test Ethernet connectivity between the Ethernet access ports on the separate ML-Series cards. To do this, use your standard Ethernet connectivity testing.

Understanding Redundant Interconnect

Ring interconnect (RI) is a mechanism to interconnect RPRs, both RPR-IEEE and Cisco proprietary RPR, for protection from failure. It does this through redundant pairs of back-to-back Gigabit Ethernet connections that bridge RPR networks. One connection is the active node and the other is the standby node. During a failure of the active node, link, or card, the detection of the failure triggers a switchover to the standby node. Figure 26-8 illustrates an example of RPR RI.

Figure 26-8 RPR RI

Characteristics of RI on the ML-Series Card

RI on the ML-Series card has these characteristics:

•Supported only on Gigabit Ethernet

•Provisioned by identifying peer RPR MACs as either primary or standby

•Uses an OAM frame to flush the spatially aware sublayer (SAS) table and MAC table at the add stations

•Provides protection between individual RPRs, including:

–Two RPRs

–Two Cisco proprietary RPRs

–A Cisco proprietary ring and an IEEE 802.17 ring

•Provides card-level redundancy when connected to a switch running EtherChannel

Caution When connecting to a switch running EtherChannel, you must configure rpr-ieee ri foreign on the primary and secondary ML-Series cards.

Caution RPR-IEEE RI requires communication over the topology between the ML-Series cards. Traffic loss can occur if there is not enough communication and more than one span is down on a ring, for any reason.

Caution If the primary ML-Series card goes to standby because the interconnect interface goes down, then the ring interface is placed administratively down (admin down). This action signals the secondary ML-Series card to go to active. At this time, if the user configures a
no shutdown on the primary ML-Series card ring interface, the ring interface comes up. This will signal the secondary ML-Series card to go to standby, which causes traffic loss. This occurs with all ML-Series card microcodes and with both RPR-IEEE and Cisco proprietary RPR.

Caution With Cisco proprietary RPR, a shutdown of the SPR interface puts ML1000-2 cards in passthrough mode. This allows the card to participate in RI. ML1000-2 cards are the only ML-Series cards eligible for RI. Other ML-Series cards fail to enter passthrough mode, when the SPR interface is shutdown.

RI Configuration Example

Excerpts of sample Cisco IOS code for an RPR RI for ML-Series-card-only connections are provided in Example 26-9 and Example 26-10. Excerpts of sample Cisco IOS code for an RPR RI where the primary and secondary ML-Series cards are connected to a foreign switch, any switch that is not an ML-Series card, are provided in Example 26-9 and Example 26-10. Status of RI can be found as illustratedin Example 26-13.

Example 26-9 Primary ML-Series Card Configuration

interface rpr-ieee0

no ip address

rpr-ieee ri mode

no shutdown

In the above example, after rpr-ieee ri mode you need to insert the MAC address of the primary peer. To fetch this address, log in to the primary peer ML-Series card and enter the command show interface rpr-ieee as follows:

The MAC address of the primary peer is 0019.076c.7f71. The configuration would now appear as rpr-ieee ri mode 0019.076c.7f71.

Example 26-10 Secondary ML-Series Card Configuration

interface rpr-ieee0

no ip address

rpr-ieee ri mode

no shutdown

In the above example, after rpr-ieee ri mode you need to insert the MAC address of the secondary peer. To fetch this address, log in to the secondary peer ML-Series card and enter the command show interface rpr-ieee as follows:

In the above example, after rpr-ieee ri mode you need to insert the MAC address of the primary peer. To fetch this address, log in to the primary peer ML-Series card and enter the command show interface rpr-ieee as follows:

In the above example, after rpr-ieee ri mode you need to insert the MAC address of the secondary peer. To fetch this address, log in to the secondary peer ML-Series card and enter the command show interface rpr-ieee as follows: